The following United States patents comprise the closest known prior art: U.S. Pat. Nos. 4,007,653, 3,901,111, 3,835,691, 3,335,627, 3,212,143, 3,079,823, 1,271,798.
In the metalworking arts, it is a common practice to use some device to remove or strip a metal workpiece from the die of a forging or stamping machine. Often the device used comprises a standard punch holder, a tool well known to the skilled craftsman. The punch holder is modified by the provision of a resilient bumper mounted on the punch holder in place of the usual metal punch.
These devices exhibit certain drawbacks which make them undesirable in some forging or stamping processes. For example, the punch holder provides direct impact on the workpiece, with the only cusioning effect being provided by the resilient bumper. If the length of travel of the work-stripping punch is not precisely controlled, the work stripper can exceed its resilient limits and damage the workpiece. The hard impact can also mar the surface of the workpiece, resulting in quality control problems. Furthermore, the resilient bumper undergoes severe stress and strain, and typically fails after relatively brief usage.